JP2022134320A - knee airbag device - Google Patents

Abstract

To provide a knee airbag device which can smoothly expand and develop an airbag in a narrow space on a front side of a knee part of an occupant.SOLUTION: An air bag 20 of a knee airbag device comprises: a first folding part 23 which is folded at a first polygonal line F1 extending in a lateral width direction B1 of the air bag 20 so that a first face 21 being an opposed surface on an occupant side becomes inside; and a second folding part 24 which is folded at a second polygonal line F2 extending along the first polygonal line F1 so that a second face 22 being an opposed surface on a vehicle side becomes inside.SELECTED DRAWING: Figure 4

Description

The present invention relates to a knee airbag device mounted on a vehicle.

Patent Literature 1 below discloses a so-called "knee airbag device," which is a knee-protecting airbag device provided with airbags that inflate and deploy to restrain both knees of an occupant. In this knee airbag device, the airbag has a folded portion in which the tip portion is folded into the airbag, and both left and right sides of the airbag with the tip portion folded in are directed in a direction to approach each other and are positioned on the side facing the vehicle body. A pair of first roll-folded parts that are roll-folded, and a second roll-folded part that is roll-folded on the side facing the vehicle body with the front end side in the deployment direction of the airbag, which is roll-folded at both left and right ends, toward the base end. , for storage.

JP 2009-101758 A

In the case of the above knee airbag device, since the tip of the airbag is folded into the airbag at the folded portion, the airbag is inflated and deployed when the resistance is large when the folded portion is released. is expected to be hindered. As a result, a problem may arise in that smooth inflation and deployment of the airbag is hindered. In particular, when the space in front of the occupant's knees becomes narrower due to variations in the physiques of the occupants (such as the height and leg length of the occupants), this problem may become more pronounced. . Therefore, in designing this type of knee airbag device, there is a demand for a technique that is effective in preventing obstruction to the inflation and deployment of the airbag even when the space in front of the occupant's knees is narrow. be done.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a knee airbag device capable of smoothly inflating and deploying an airbag even in a narrow space on the front side of an occupant's knees. .

One aspect of the present invention is a knee airbag device mounted on a vehicle,
a housing portion provided in a vehicle interior portion located in front of the knees of the occupant;
an airbag housed in the housing section so as to be inflatable and deployable in a facing space between the occupant's knees and the vehicle interior;
a gas supply unit that supplies gas for inflation and deployment to the airbag;
with
When the airbag has a surface facing the knees of the occupant in the inflated and deployed state in the facing space, and a surface facing the vehicle interior portion is a vehicle-side facing surface, the airbag has an occupant-side facing surface. a first folded portion folded back along a first fold line extending in the lateral width direction of the airbag so that one of the facing surface and the vehicle-side facing surface faces inward; and the occupant-side facing surface and the vehicle-side facing surface. and a second folded portion folded back along a second folding line extending along the first folding line so that one of the other surfaces faces inward.

In the knee airbag device of the aspect described above, the airbag is accommodated in the accommodation portion provided in the vehicle interior portion located forward of the knees of the occupant. The airbag protrudes from the storage section and inflates and deploys in the facing space between the occupant's knees and the interior of the vehicle by the supply of gas for inflation and deployment from the gas supply section.

This airbag is provided with at least a first folded portion and a second folded portion. Here, the first folded portion is a portion that is folded back along a first folding line extending in the lateral width direction of the airbag so that either one of the occupant-side facing surface and the vehicle-side facing surface faces inward. On the other hand, the second folded portion is a portion that is folded back at a second folding line extending along the first folding line so that the other of the occupant-side facing surface and the vehicle-side facing surface faces inward.

When the airbag is deployed and inflated, the first folded portion and the second folded portion are unfolded at the respective folding lines. At this time, if the folding direction of the first folding portion at the first folding line and the folding direction of the second folding portion at the second folding line are in the same relationship, the airbag is deployed. The vector is formed in a direction that is always biased toward either the occupant side or the vehicle side. Therefore, when the space on the front side of the occupant's knees is a narrow space, it may interfere with the inflating and deploying operation of the airbag.

Therefore, the folding direction of the first folding portion at the first folding line and the folding direction of the second folding portion at the second folding line are opposite to each other. The movements of the two folded parts when unfolded can be made different from each other. As a result, the deployment vectors generated in the airbag are the occupant side or the vehicle side when the first folded portion is unfolded along the first folding line and when the second folded portion is unfolded along the second folding line. change to the side.

At this time, by synthesizing the deployment vector in the direction toward the vehicle and the deployment vector in the direction toward the occupant, it is possible to obtain the deployment vector in the direction toward the occupant's knees. directivity of the airbag can be enhanced. Therefore, even when the space on the front side of the occupant's knees is a narrow space, the airbag slips through the narrow space and smoothly inflates and deploys.

As described above, according to the above aspect, it is possible to provide a knee airbag device that can smoothly inflate and deploy the airbag even in a narrow space on the front side of the knees of the occupant.

1 is a diagram showing an overview of the configuration of a knee airbag device according to Embodiment 1; FIG. FIG. 2 is a plan view showing the airbag in FIG. 1 in an unfolded state before being folded; FIG. 2 is a cross-sectional view taken along line III-III of FIG. FIG. 3 is a plan view showing the airbag of FIG. 2 with a plurality of fold lines; FIG. 5 is a plan view showing the airbag of FIG. 4 in a state folded back along a first folding line; FIG. 5 is a cross-sectional view taken along line VI-VI. FIG. 6 is a plan view showing the airbag of FIG. 5 folded back along a second folding line; A cross-sectional view taken along line VIII-VIII in FIG. 7 . FIG. 8 is a plan view showing the airbag of FIG. 7 folded back along a third folding line; FIG. 2 is a cross-sectional view schematically showing how the airbag in FIG. 1 is inflated and deployed at an initial stage; FIG. 2 is a cross-sectional view schematically showing how the airbag in FIG. 1 is inflated and deployed at a later stage; Sectional drawing which expands and shows FIG. 11 partially. FIG. 2 is a cross-sectional view schematically showing how the airbag in FIG. 1 is inflated and deployed at the final stage; FIG. 5 is a plan view corresponding to FIG. 4 of the airbag according to the second embodiment;

Preferred embodiments of the above aspects are described below.

In the above-described mode, "inflating and deploying" refers to an operation in which an airbag that has been folded into a predetermined shape in advance expands by being supplied with gas so as to release the folded state while inflating.

In the knee airbag device of the aspect described above, the airbag has a plurality of chambers partitioned by a plurality of tethers,
It is preferable that the first fold line is provided in a knee chamber of the plurality of chambers, which is sandwiched between the occupant's knee and the vehicle interior portion in the inflated and unfolded state in the facing space.

According to this knee airbag device, before the knee chamber of the airbag is completely inflated, the first folded portion can be unfolded along the first folding line. Therefore, it is possible to prevent the knee chamber of the airbag from being completely inflated and reaching the region above the knee of the occupant.

In the knee airbag device of the aspect described above, the airbag has a plurality of chambers partitioned by a plurality of tethers, the plurality of chambers including a large-capacity chamber having the largest expansion capacity, Preferably, the large-capacity chamber is provided with the first folding line.

According to this knee airbag device, before the large-capacity chamber of the airbag is completely inflated, the first folded portion can be unfolded along the first folding line. Therefore, it is possible to prevent the large-capacity chamber from being completely inflated and hindering the inflation and deployment operation of the airbag.

In the knee airbag device of the above-described aspect, the airbag has a plurality of chambers partitioned by a plurality of tethers, and the plurality of chambers include a front surface of the occupant's lower leg in an inflated and deployed state in the facing space. It is preferable that a narrowing chamber positioned at a portion where the gap between the part and the vehicle interior part is the narrowest is included, and the first folding line is provided in the narrowing chamber.

According to this knee airbag device, before the narrowing chamber of the airbag is completely inflated, the first folded portion can be unfolded at the first folding line. Therefore, it is possible to prevent the narrowing chamber from being completely inflated and hindering the inflation and deployment operation of the airbag.

In the knee airbag device of the aspect described above, the first folded portion is folded back along the first fold line so that the occupant-side facing surface of the airbag faces inward, and the second folded portion is folded back along the first folding line. It is preferable that after the first folded portion is folded back, the airbag is folded back along the second folding line so that the vehicle-side facing surface of the airbag faces the inside.

In this knee airbag device, when the airbag is inflated and deployed, the second folded portion is unfolded prior to the first folded portion. At the initial stage when the second folded portion is unfolded, the airbag contacts the vehicle interior portion at its vehicle-side facing surface. After that, in the later stage when the first folded portion is unfolded, the airbag contacts the occupant's knees with its occupant-side facing surface. Therefore, it is possible to reduce the contact load that the occupant receives from the airbag in the initial stage.

A specific example of the knee airbag device of the present embodiment will be described below with reference to the drawings.

In the drawings of this specification, unless otherwise specified, the arrow X indicates the vehicle width direction, the arrow Y indicates the front of the vehicle, and the arrow Z indicates the upper side of the vehicle. Arrow A indicates the inflation and deployment direction of the knee airbag, arrow B1 indicates the widthwise direction (front-rear direction) of the airbag in an expanded state before folding, and arrow B1 indicates the direction in which the airbag is expanded before folding. The vertical width direction (horizontal direction) in the state is indicated by an arrow B2, and the thickness direction of the airbag is indicated by an arrow B3.

(Embodiment 1)
As shown in FIG. 1, a knee airbag device 101 of Embodiment 1 is mounted on a vehicle. The knee airbag device 101 is provided for an occupant C seated in a front seat (not shown) of a vehicle, and functions to mainly restrain and protect the knees K of the occupant C in the event of a vehicle collision. .

The knee airbag device 101 includes a housing portion 10, an airbag 20 as a knee airbag for knee protection, and an inflator 30 as a gas supply portion.

The housing portion 10 is provided in the panel lower portion 2, which is a vehicle interior portion, positioned in front of the knee portion K of the occupant C in the instrument panel 1. As shown in FIG. The housing portion 10 is opened at a position facing the lower leg front portion La of the occupant C, and the opening portion is covered by an airbag door 2a provided in the lower portion 2 of the panel. At this time, the lower leg front portion La refers to a region on the front side of the lower leg L, which is a region from the knee K of the occupant C to the ankle through the shin.

The housing portion 10 has a housing space for housing the airbag 20 together with the inflator 30 . The housing portion 10 may be configured by forming a portion of the instrument panel 1 into the shape of a case, or may be configured by a case separate from the instrument panel 1 .

A protruding portion 3 protruding toward the knee K of the occupant C is provided at a position facing the knee K of the occupant C in the panel lower portion 2 of the instrument panel 1 . The narrow space Sa between the knee K and the projecting portion 3 is a space in which the gap in the longitudinal direction of the vehicle is the smallest among the facing spaces S between the knees K of the occupant C and the panel lower portion 2 .

The airbag 20 is formed in the shape of a bag by stitching a plurality of base fabrics, and is housed in the housing portion 10 in a pre-folded state in a predetermined shape so that it can be inflated and deployed in the facing space S. . The airbag 20 is configured to extend in the deployment direction A obliquely upward along the panel lower portion 2 in the facing space S when inflated and deployed. Inflating and deploying at this time refers to an operation in which the airbag 20, which has been folded into a predetermined shape in advance, expands while being supplied with gas so as to release the folded state.

The inflator 30 has a gas generating port (not shown) communicated with the internal space of the airbag 20, and is configured to supply gas for inflation and deployment to the internal space of the airbag 20 during operation. The inflator 30 operates according to a control signal output from a control unit (ECU) 103 when the collision detection sensor 102 detects a vehicle collision. Both the collision detection sensor 102 and the control unit 103 are mounted on the vehicle, and constitute an occupant protection system for protecting the occupant C together with the knee airbag device 101 .

The airbag 20 starts to inflate and deploy when supplied with gas from the inflator 30 . At this time, the airbag door 2a is opened by the load received from the airbag 20, so that the airbag 20 protrudes from the housing portion 10 and enters the opposing space S between the knees K of the occupant C and the panel lower portion 2. Inflate and expand. The airbag 20 is tethered from the inside by a plurality of tethers 41, 42, 43, which are tethering members, to prevent the airbag 20 from being inflated and deployed beyond a certain size.

The airbag 20 inflated and deployed between both knees K of the occupant C and the panel lower portion 2 functions to restrain at least both knees K of the occupant C. The restraint referred to here includes a mode in which both knees K of the occupant C are restricted from moving forward due to the reaction force due to the internal pressure of the airbag 20, and a movement in which both knees K of the occupant C are restricted from opening outward. , a mode in which the occupant C floats upward Z of the vehicle, and the like. As a result, both knees K of the occupant C can be restrained from moving in the vehicle width direction X, the vehicle forward Y, and the vehicle upward Z direction.

FIG. 2 shows the airbag 20 in an unfolded unfolded state C1 before folding. This airbag 20 has four chambers 20a, 20b, 20c, 20d partitioned by three tethers 41, 42, 43. As shown in FIG.

Each of the three tethers 41, 42, and 43 is formed in a long belt shape (also referred to as "belt shape" or "thin plate shape"), and both ends of the tethers in the width direction are attached to the airbag by means of stitching, bonding, or the like. It is joined to the inner wall surface. Each of the three tethers 41, 42, 43 is typically made of the base cloth used for the airbag 20 or the webbing material used for the seat belt. Each of the three tethers 41, 42, 43 has a plurality of gas flow openings 41a, 42a, 43a arranged side by side in the width direction B1. Gas can flow.

With regard to the airbag 20 in the unfolded state C1, when the end on the side of the inflator 30 in the longitudinal width direction B2 is the base end and the end on the opposite side of the inflator 30 in the longitudinal width direction B2 is the distal end, three tethers are provided. The tethers 41, 42, 43 are arranged in the order of the first tether 41, the second tether 42, and the third tether 43 from the base end side to the tip end side in the longitudinal width direction B2.

The four chambers 20a, 20b, 20c, and 20d are arranged in the order of the first chamber 20a, the second chamber 20b, the third chamber 20c, and the fourth chamber 20d from the base end side to the front end side in the longitudinal width direction B2. formed. In this embodiment, the three chambers 20a, 20b, 20c are configured to have generally similar expansion capacities.

On the other hand, the fourth chamber 20d is a large-capacity chamber having the largest expansion capacity among the four chambers 20a, 20b, 20c, and 20d. The fourth chamber 20d is a knee chamber sandwiched between the knee K of the occupant C and the lower panel 2 in the inflated and unfolded state in the facing space S, and furthermore, the front lower leg portion La of the occupant C and the lower panel. 2 is a narrowing chamber located in the narrow space Sa where the gap with 2 is the narrowest.

Gas supplied from the inflator 30 first fills the first chamber 20 a of the internal space of the airbag 20 . As a result, the airbag 20 starts to inflate and deploy. This gas flows into the second chamber 20b through the plurality of gas flow openings 41a of the first tether 41 while filling the first chamber 20a. The gas further flows into the third chamber 20c through the plurality of gas flow openings 42a of the second tether 42 while filling the second chamber 20b. The gas further flows into the fourth chamber 20d through the plurality of gas flow openings 43a of the third tether 43 while filling the third chamber 20c. Then, the fourth chamber 20d is filled with gas until the airbag 20 is inflated and deployed to a predetermined state.

In addition, the number of tethers is not limited to three, and the number of chambers is not limited to four, and each number can be appropriately changed as necessary. For example, it is preferable to set the number of tethers and chambers in consideration of the physique of the occupant C (for example, the height of the occupant C, the length of the leg L (see FIG. 1), etc.). As a result, the airbag 20 can be appropriately inflated and deployed in accordance with the assumed physique of the occupant C.

As shown in FIG. 3, the airbag 20 in the unfolded state C1 has a first surface 21 and a second surface 22 facing each other in the thickness direction B3. The airbag 20 has a first surface 21 that faces the knee K (see FIG. 1) of the occupant C in an inflated and deployed state in the facing space S, and a second surface 22 that faces the vehicle. It becomes a vehicle-side facing surface facing the interior portion 2 (see FIG. 1).

As shown in FIG. 4 , the airbag 20 is provided with a first folded portion 23 , a second folded portion 24 and a third folded portion 25 .

The first folded portion 23 is a portion that is folded back along one first folding line F1 extending in the lateral width direction B1 of the airbag 20 so that the first surface 21 faces inward. The first folding line F1 is set closer to the distal end in the longitudinal width direction B2 than the third tether 43 is. Assuming that the dimension of the first folded portion 23 in the vertical width direction B2 is the folded amount, it is preferable to appropriately set the folded amount for each package. Versatility of the knee airbag device 101 can be enhanced by changing the amount of folding of the first folding portion 23 according to the vehicle type or the like on which the knee airbag device 101 is mounted.

After the first folded portion 23 has been folded, the second folded portion 24 has a plurality of (three in FIG. 4) second folded portions extending in parallel along the first folding line F1 with the second surface 22 facing inward. This is the part that is folded back at the line F2. All of the plurality of second folding lines F2 are located on the base end side in the longitudinal width direction B2 relative to the third tether 43 and the first folding line F1, are adjacent to the first folding line F1, and are spaced apart from each other in the longitudinal width direction B2. are set apart.

After the second folded portion 24 has been folded, the third folded portion 25 is formed so that the second surface 22 faces inward, and the left and right ends of the lateral width direction B1 are a plurality of portions that are perpendicular to the first folded line F1 (in FIG. ) is folded back at the third folding line F3.

Next, the manner in which the airbag 20 is folded will be described with reference to FIGS. 4 to 9. FIG.

As shown in FIG. 4, first, the front end portion of the airbag 20 in the unfolded state C1 in the longitudinal width direction B2 is folded back along the first folding line F1 in the first direction D1. As a result, as shown in FIGS. 5 and 6, the airbag 20 changes from the unfolded state C1 to the folded state C2. In the airbag 20 in the folded state C2, the first folded portion 23 is formed on the first surface 21 side.

Next, the front end portion of the airbag 20 in the folded state C2 in the longitudinal width direction B2 is folded back along the second folding line F2 in the second direction D2 opposite to the first direction D1 (see FIG. 5). At this time, since the airbag 20 has a plurality of second folding lines F2, the airbag 20 is folded back into a roll in the second direction D2. As a result, as shown in FIGS. 7 and 8, the airbag 20 changes from the folded state C2 to the folded state C3. The second folded portion 24 is formed on the second surface 22 side of the airbag 20 in the folded state C3.

Finally, the left and right ends of the airbag 20 in the folded state C3 in the width direction B1 are folded back along the third folding line F3 in the third direction D3 (see FIG. 7). At this time, since the airbag 20 has a plurality of third folding lines F3, both left and right ends of the airbag 20 are folded back in the third direction D3. As a result, as shown in FIG. 9, the airbag 20 changes from the folded state C3 to the folded state C4. In the airbag 20 in the folded state C4, a pair of left and right third folded portions 25 are formed on the second surface 22 side. Then, the airbag 20 is accommodated in the accommodation portion 10 in the folded state C4.

Next, an operation of inflating and deploying the airbag 20 of the knee airbag device 101 of Embodiment 1 will be described mainly with reference to FIGS. 10 to 13. FIG.

As shown in FIG. 10, gas generated when the inflator 30 is activated is supplied to the internal space of the airbag 20 . At this time, the vehicle rear side of the facing area S extends from the shin to the knee K along the front leg portion La of the occupant C, and the vehicle front side of the facing area S extends along the panel lower portion 2 . Therefore, the airbag 20 starts to deploy and inflate in the deployment direction A below the facing area S in the initial stage E1.

The airbag 20 in the folded state C4 (see FIG. 9) deploys so as to release the pre-folded state. As for the deployment of the airbag 20, first, by unfolding the third folded portion 25 along the third folding line F3 from the folded state C4, the airbag 20 becomes the folded state C3 shown in FIG. After that, by unfolding the second folded portion 24 along the second folding line F2 from the folded state C3, the airbag 20 becomes the folded state C2 shown in FIG. By unfolding the first folded portion 23 along the first folding line F1 from the folded state C2, the airbag 20 returns to a state close to the unfolded state C1 shown in FIG.

As shown in FIG. 11, the airbag 20 begins to deploy and inflate from the first chamber 20a, which is closer to the inflator 30, to the second chamber 20b, the third chamber 20c, and the fourth chamber 20d in that order. At this time, the gas in the first chamber 20a flows into the second chamber 20b through the gas flow opening 41a of the first tether 41. As shown in FIG. The gas flowing into the second chamber 20b flows through the gas flow opening 42a of the second tether 42 into the third chamber 20c. The gas that has flowed into the third chamber 20c flows through the gas flow opening 43a of the third tether 43 into the fourth chamber 20d. The second chamber 20b expands above the first chamber 20a, the third chamber 20c expands above the second chamber 20b, and the fourth chamber 20d expands above the third chamber 20c.

In the inflation and deployment process in which the airbag 20 changes from the folded state C3 (see FIG. 7) to the folded state C2 (see FIG. 5), the second folded portion 24 is rolled back in the second direction D2. The roll unwinds in the first direction D1, which is the opposite direction from . At this time, since the second folded portion 24 is arranged to face the panel lower portion 2 , it makes a constant movement to continue the roll release operation in the first direction D1 while contacting the panel lower portion 2 .

The latter stage E2 of the airbag 20 shown in FIG. 11 is a stage during which the airbag 20 returns from the folded state C2 (see FIG. 5) to a state close to the unfolded state C1 (see FIG. 4). . In this later stage E2, before the fourth chamber 20d is completely inflated, the first folded portion 23 is unfolded at the first folding line F1. The first folded portion 23 is folded back in the second direction D2 (the two points in FIG. 11) from the state of being folded back in the first direction D1 (the state indicated by the solid line in FIG. 11). state indicated by a dashed line).

Therefore, the fourth chamber 20d of the airbag 20 can move upward through the narrow area Sa to the upper knee area of the knee K of the occupant C before being fully inflated. At this time, since the first folded portion 23 is arranged to face the knee portion K of the occupant C, the movement of continuing the folding operation in the second direction D2 while contacting the knee portion K, that is, the second folding portion 23 It moves in the opposite direction to the folding part 24 .

As shown in FIG. 12 , since the airbag 20 is provided with the first folded portion 23 , in the later stage E2, when the airbag 20 is inflated and deployed in the opposing space S, the deployment vector Va in the direction toward the panel lower portion 2 and the occupant A development vector Vc in the direction toward the knees K of the occupant C (that is, deployment direction A) is obtained by synthesizing with the development vector Vb in the direction toward the front leg portion La of the occupant C. Therefore, the directivity of the deployment direction A of the fourth chamber 20d of the airbag 20 can be enhanced. Even in the case where the fourth chamber 20d is attached, it is possible to prevent the fourth chamber 20d from being caught on the panel lower portion 2 or the lower leg front portion La.

As shown in FIG. 13 , in the final stage E3 of the airbag 20, the fourth airbag 20, which is located in the facing space S between both knees K of the occupant C and the projecting portion 3 of the panel lower portion 2, is located on the frontmost side. A chamber 20d is arranged. Therefore, in the final stage E3 of the airbag 20, a desired pressing load acting on the knees of the occupant C from the airbag 20 can be ensured. At this time, the fourth chamber 20d of the airbag 20 restrains both knees K of the occupant C, thereby suppressing both knees K from moving in the vehicle width direction X and the vehicle forward direction Y.

Also, three chambers 20a, 20b, 20c are arranged in the facing space S between both shins of the occupant C and the panel lower portion 2. As shown in FIG. The three chambers 20a, 20b, and 20c have a smaller inflation capacity than the fourth chamber 20d, and are configured such that the dimension in the thickness direction B3 of the airbag 20 when inflated is smaller than that of the fourth chamber 20d. That is, the airbag 20 is thinned at portions corresponding to the three chambers 20a, 20b, and 20c. Therefore, at the final stage E3 of the airbag 20, the pressing load acting from the airbag 20 on the shins of the occupant C can be kept small.

Next, the effects of the first embodiment described above will be described.

In the knee airbag device 101 configured as described above, the airbag 20 is housed in the housing portion 10 provided in the panel lower portion 2 located in front of the knee portion K of the occupant C. As shown in FIG. The airbag 20 protrudes from the housing portion 10 and inflates and deploys in the opposing space S between the knee portion K of the occupant C and the panel lower portion 2 by the supply of gas for inflation and deployment from the inflator 30 .

The airbag 20 is provided with at least a first folded portion 23 and a second folded portion 24 . Here, the first folded portion 23 is a portion that is folded back along the first folding line F1 so that the first surface 21 of the airbag 20 faces inside. On the other hand, the second folded portion 24 is a portion that is folded back along the second folding line F2 so that the second surface 22 of the airbag 20 faces inside.

When the airbag 20 is deployed and inflated, the first folded portion 23 and the second folded portion 24 are unfolded at the folding lines F1 and F2, respectively. At this time, the folding direction (first direction D1) of the first folding portion 23 along the first folding line F1 and the folding direction (second direction D2) of the second folding portion 24 along the second folding line F2. , are oriented in the same direction, the deployment vector generated in the airbag 20 is always biased toward either the occupant side or the vehicle side. Therefore, when the space in front of the knees K of the occupant C is a narrow space Sa, the inflation and deployment operation of the airbag 20 may be hindered.

Therefore, the folding direction (first direction D1) of the first folding portion 23 at the first folding line F1, the folding direction (second direction D2) of the second folding portion 24 at the second folding line F2, are opposite to each other, the movements of the two folded portions 23 and 24 when the folding is released at the respective folding lines F1 and F2 can be made different from each other. As a result, the deployment vectors generated in the airbag 20 are different when the first folded portion 23 is unfolded along the first folding line F1 and when the second folded portion 24 is unfolded along the second folding line F2. , changes to the occupant side or the vehicle side.

At this time, by synthesizing the developed vector Va directed toward the vehicle and the developed vector Vb directed toward the passenger, a developed vector Vc directed toward the knees K of the occupant C (upward deployment direction A) is obtained. , and the directivity of the airbag 20 can be enhanced so that it is directed toward the knees K of the occupant C. Therefore, even when the space in front of the knees K of the occupant C is a narrow space Sa, the airbag slips through the narrow space Sa and smoothly inflates and deploys.

Therefore, according to the first embodiment described above, it is possible to provide the knee airbag device 101 that can smoothly inflate and deploy the airbag 20 even in the narrow space Sa on the front side of the knees K of the occupant C. Become.

According to the knee airbag device 101 configured as described above, the folding of the first folding portion 23 at the first folding line F1 can be released before the fourth chamber 20d of the airbag 20 is completely inflated. Therefore, it is possible to prevent the fourth chamber 20d of the airbag 20 from being completely inflated and reaching the above-the-knee region of the occupant C (obstructing the inflation and deployment operation of the airbag 20).

According to the knee airbag device 101 configured as described above, when the airbag 20 is inflated and deployed, the second folded portion 24 is unfolded prior to the first folded portion 23 . At the initial stage E1 when the second folded portion 24 is unfolded, the second surface 22 of the airbag 20 contacts the panel lower portion 2 . After that, in the latter stage E2 when the first folded portion 23 is unfolded, the first surface 21 of the airbag 20 comes into contact with the knee portion K of the occupant C. As shown in FIG. Therefore, the contact load that the occupant C receives from the airbag 20 in the initial stage E1 can be reduced.

In the modified example particularly related to the first embodiment described above, the first folded portion 23 is folded back along the first folding line F1 so that the second surface 22 of the airbag 20 faces inward, and the airbag 20 is folded back along the first fold line F1. It is possible to employ a configuration in which the second folded portion 24 is folded back along the second folding line F2 so that the one surface 21 faces inward.

In the case of this configuration, when the roll of the second folded portion 24 is unrolled during the inflation and deployment process of the airbag 20, the second folded portion 24 moves along the occupant C and continues the unrolling operation. After that, the first folded portion 23 is unfolded at the first folding line F1 while coming into contact with the panel lower portion 2. - 特許庁

Further, in another modification particularly related to the first embodiment described above, in order to improve the self-sustainability of the airbag 20 in the facing space S, at least the expansion capacity of the first chamber 20a is increased by the second chamber 20b and the third chamber 20b. 20c can be set to exceed the expansion capacity, or all four chambers 20a, 20b, 20c, 20d can be set to have substantially similar expansion capacities. That is, the relative sizes of the expansion capacities of the four chambers 20a, 20b, 20c, 20d can be appropriately set as required.

In another modification particularly related to the first embodiment described above, at least one of the three chambers 20a, 20b, 20c among the four chambers 20a, 20b, 20c, 20d has the first folding line F1. can be adopted. In the case of this configuration, when the second folding line F2 is set closer to the leading end portion side in the longitudinal width direction B2 than the first folding line F1, the first folded portion 23 is positioned at the second folding line F2 of the second folded portion 24. is folded back at the first folding line F1.

Other embodiments related to the first embodiment described above will be described below with reference to the drawings. In other embodiments, the same reference numerals are given to the same elements as those of the first embodiment, and the description of the same elements will be omitted.

(Embodiment 2)
As shown in FIG. 14, the airbag 120 according to the second embodiment differs from the airbag 20 according to the first embodiment. The airbag 120 is provided with a bellows folded portion 123 and a roll folded portion 124 .

In the bellows-folded portion 123, first folding lines L1 and second folding lines L2 are alternately set in the vertical width direction B2. Therefore, the accordion-folded portion 123 is configured to be folded back in the first direction D1 along the first folding line L1 and also folded back in the second direction D2 along the second folding line L2. At this time, the bellows-folded portion 123 has a portion (first folded portion) corresponding to the first folded portion 23 of the first embodiment and a portion (second folded portion) corresponding to the second folded portion 24 of the first embodiment. This part has both. On the other hand, the roll-folded portion 124 is a portion corresponding to the second folded-back portion 24 of the first embodiment.

Other configurations are the same as those of the first embodiment.

According to the second embodiment described above, by adopting the bellows folded portion 123 in the airbag 120, the directivity toward the knees K of the occupant C when the airbag 120 is deployed and inflated is reduced to the airbag of the first embodiment. It becomes possible to raise it more than the case of 20.

In addition, the same effects as those of the first embodiment are obtained.

The present invention is not limited to the exemplary embodiments described above, and various applications and modifications are conceivable without departing from the scope of the present invention. For example, it is also possible to implement the following forms that apply the above embodiments.

In the first embodiment described above, the fourth chamber 20d of the airbag 20 corresponds to all of the knee chamber, the large-capacity chamber, and the narrow chamber. At least one of a partial chamber, a large volume chamber, and a narrow chamber can be configured accordingly.

In view of the above-described embodiment and other modified examples, the following aspects are conceivable.

As one aspect,
"A storage section provided in the vehicle interior located forward of the knees of the occupant,
an airbag housed in the housing section so as to be inflatable and deployable in a facing space between the occupant's knees and the vehicle interior;
a gas supply unit that supplies gas for inflation and deployment to the airbag;
with
When the airbag is inflated and deployed in the facing space, the airbag deploys in the direction toward the occupant's knees by synthesizing the deployment vector in the direction toward the interior of the vehicle and the deployment vector in the direction toward the front portion of the lower leg of the occupant. A knee airbag device that is folded in such a folding manner that a vector is obtained. ”
A mode can be adopted.

According to this aspect, as in the case of the above-described embodiment, the deployment vector in the direction toward the knees of the occupant can be obtained, so the directivity of the airbag can be increased so that it moves toward the knees of the occupant. Therefore, even when the space in front of the occupant's knees is a narrow space, the airbag can pass through the narrow space and be smoothly inflated and deployed.

2 Vehicle Interior Part 10 Storage Part 20 Airbag 20a, 20b, 20c Chamber 20d Chamber (Knee Chamber, Large Capacity Chamber, Narrow Chamber)
21 First surface (occupant side facing surface)
22 Second surface (vehicle side facing surface)
23 First folded portion 24 Second folded portion 30 Inflator (gas supply portion)
41, 42, 43 tether 101 knee airbag device 120 airbag 123 bellows folded portion (first folded portion, second folded portion)
124 roll folding section (second folding section)
B1 Width direction of airbag C Occupant F1 First fold line F2 Second fold line K Knee S Opposing space

Claims (5)

a housing portion provided in a vehicle interior portion located in front of the knees of the occupant;
an airbag housed in the housing section so as to be inflatable and deployable in a facing space between the occupant's knees and the vehicle interior;
a gas supply unit that supplies gas for inflation and deployment to the airbag;
with
When the airbag has a surface facing the knees of the occupant in the inflated and deployed state in the facing space, and a surface facing the vehicle interior portion is a vehicle-side facing surface, the airbag has an occupant-side facing surface. a first folded portion folded back along a first fold line extending in the lateral width direction of the airbag so that one of the facing surface and the vehicle-side facing surface faces inward; and the occupant-side facing surface and the vehicle-side facing surface. and a second folded portion folded back along a second folding line extending along the first folding line so that one of the surfaces faces inward. The airbag has a plurality of chambers partitioned by a plurality of tethers,
2. The method according to claim 1, wherein the first fold line is provided in a knee chamber of the plurality of chambers, which is sandwiched between the occupant's knee and the vehicle interior portion in an inflated and unfolded state in the facing space. A knee airbag device as described. The airbag has a plurality of chambers partitioned by a plurality of tethers, the plurality of chambers including a large-capacity chamber having the largest expansion capacity, and the large-capacity chamber extending along the first fold line. 2. The knee airbag device of claim 1, wherein a is provided. The airbag has a plurality of chambers partitioned by a plurality of tethers, and in the plurality of chambers, there is a gap between the occupant's lower leg front portion and the vehicle interior portion in the inflated and deployed state in the facing space. 2. The knee airbag device of claim 1, further comprising a constriction chamber located at the narrowest point, wherein said constriction chamber is provided with said first fold line. The first folded portion is folded back along the first fold line so that the occupant-side facing surface of the airbag faces inward, and the second folded portion is folded back after the first folded portion is folded. The knee airbag device according to any one of claims 1 to 4, wherein the bag is folded back along the second fold line so that the vehicle-side facing surface of the bag faces inside.

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